Pump control for dispensing liquid additives



E. M. VODA 3,4@6,71@

PUMP CONTROL FOR DISPENSING LIQUID ADDITIVES 2 Sheets-Sheet 1 Filed May 1, 1964 mmvron flzzyaae JV l oa az A TTORNE YS E. M. VODA 3,406,7W

PUMP CONTROL FOR DISPENSING LIQUID ADDITIVES (Wei 22, 1968 2 Sheets-Sheet 2 Filed May 1. 1964 3% ATTUR m i m If", I I

United States Patent of Delaware Filed May 1, 1964, Ser. No. 364,091 1 Claim. (Cl. 137-394) The present invention relates to laundry machines, and more specifically, to automatic laundry machines in which there is incorporated a dispensing system for liquid additives.

The introduction of liquid laundry additives, particularly bleach, must be accomplished at a suitable time in the programmed sequence of the washing machine cycle if suitable results are to be achieved. For example, it is advisable to delay the introduction of bleach until sometime after the detergent has been applied to the fabrics as otherwise all of the inherent whitening power of the detergent might not be realized. Furthermore, the bleach should obviously be introduced only when there is an ample amount of laundry liquid in the tub to avoid an excessive concentration of bleaching agent which might damage the fabrics.

Various dispensing systems have been suggested in the past for introducing materials such as bleach or other laundry additives into the tub at the appropriate time in the washing sequence. For the most part, however, these devices involve the use of solenoids, actuating motors, and the like and add more to the cost of the machine than would be justified. The need still remains, therefore, for a simple but foolproof additive dispenser for use in conjunction with washing machines of the automatic type wherein the dispenser can be provided at an almost negligible cost. The satisfaction of that need is the principal object of the present invention.

' Another object of the invention is to provide a delayed action liquid dispenser for automatic washing machines which employs a venturi as the means for injecting the liquid additive into the recirculating laundry liquid.

Still another object of the invention is to provide a liquid dispenser for automatic washing machines which requires no electrical energization or control circuitry whatever.

' Another object of the invention is to provide a liquid dispenser for automatic washing machines which does not interfere with the normal programming of the washing and rinsing cycles.

A further object of the invention is to provide a liquid dispenser for washing machines which is operable only when a sufiicient level of liquid exists in the machine.

In accordance with the present invention, 1 provide a laundry machine of the type including means for recirculating the laundry liquid periodically with a storage compartment for the liquid laundry additive, and connect the recirculating system with the additive storage system by means of a venturi. The venturi is located at the outlet of the tub, and as the laundry liquid flows through the outlet as part of the recirculation cycle, it causes a negative pressure to appear at the dispenser conduit, thus causing the additive fluid to be drawn into the recirculating laundry liquid stream. Means may also be provided, if required, for preventing air from entering the recirculation stream. The dispenser may also be provided with a trap which prevents discharge of the liquid contents of the dispenser until such time as the recirculation system is in operation and provides the pressure differential necessary to start the dispensing action.

A further description of the present invention will be made in conjunction with the attached sheets of drawings which illustrate a preferred embodiment of the invention as applied to an automatic washing machine.

3,406,710 Patented Oct. 22, 1968 ice In the drawings:

FIGURE 1 is a view in perspective of an automatic washing machine embodying the structure of the present invention, with portions thereof broken away for purposes of clarity;

FIGURE 2 is a view in elevation of the tub and dispenser assembly partially in cross-section; and

FIGURE 3 is a cross-sectional view of the venturi assembly shown in FIGURES 1 and 2.

As shown in the drawings:

The automatic dispensing assembly of the present invention can be employed in many diflferent types of washing machines including both horizontal and vertical axis domestic washing machines and in various types of com mercial laundry apparatus. It should be understood, therefore, that the particular machine herein described is merely exemplary of a type of machine in which the devices of the present invention find utility.

The particular machine shown in the drawings is a vertical axis laundry machine generally indicated at refer ence numeral 10 and including a cabinet 11 provided with an upwardly opening access lid 12. A splash shield 13 forms part of the back assembly of the cabinet, and a control panel 14 including the normal sequence control knob 16 are mounted forwardly of the splash shield 13. The control knob 16, of course, is designed to set the machine for automatic operation through a programmed schedule of washing, rinsing and extraction periods.

An agitator assembly for the washing machine has been indicated generally at reference numeral 17, the agitator 17 being enclosed and mounted for oscillation within a tub 18.

Liquid is delivered into the washing machine by means of a hose 19 which communicates with a water inlet solenoid 21 and a water inlet 22 for introducing water into the fora-ruinous basket (not shown) in which the articles to be washed are located. If desired, an air gap vacuum break 23 may also be provided.

The washing machine assembly is provided with a bidirectional flow pump 24 which is driven by a suitable drive motor 25. Recirculation of the laundry liquid is periodically achieved by the pump 24 which has an inlet line 27 fed from a discharge in the tub 18 (as will be described more completely hereinafter) and a discharge conduit 26 which delivers the recirculating fluid back into the tub 18, The pump is also arranged to discharge laundry liquid from the tub by means of a drain conduit 28.

The mechanism described thus far is fairly standard with automatic washing machines and has been included in the drawings merely to show the type of organization with which the improved dispenser of the present invention can be employed.

In order to avoid the possibility of injecting a concentrated bleach solution into a tub which is insufiiciently filled with washing liquid, the motor 25 (and consequently the pump 27) is under the control of a liquid level sensing device, generally indicated at numeral 30. The sensor may be air operated, liquid operated, or may consist of a simple float switch. The sensing device 30 is attached to the tub 18 by means of a flange 40, and a pair of electrical conductors 45 and 50 connect the switch portion of the sensing device to the motor 25, to prevent its energization until such time as a suflicient liquid level exists in the tub. The sensing device 30 may also operate to limit the amount of liquid appearing in the tub by cutting off the motor 25 'and/ or the water inlet solenoid 21 when a predetermined maximum level is reached.

The container for the liquid bleach or other laundry additive has been identified at reference numeral 31 in the drawings. As indicated in FIGURES 1 and 2, the container 31 has an outwardly extending flanged bracket 32 which permits it to be mounted conveniently on the rim of the tub 18; The container 31 may be made of any suitable material such as a plastic material which is resistant to the chemical action of the bleach concentrate 33 or other laundry additive to be added periodically into the Washing machine.

The lower end of the container 31 is formed with a restricted orifice 34 through which the liquid additive is discharged. A flexible conduit 36 having a gooseneck portion 37 below the discharge outlet 34 and a return bend 38 disposed above the inlet opening of the container 31 delivers the liquid into the recirculating laundry liquid stream. The bend 38 is also above the maximum permissible liquid level existing in the tub 18. The gooseneck portion 37 and the return bend 38 serve as a trap for preventing discharge of liquid from the container 31 except when a negative pressure is applied through the conduit 36.

As best illustrated in FIGURE 3 of the drawings, the conduit 36 terminates about a fitting 39 having a relatively small orifice 41 formed therein. The orifice 41 is in fluid communication with a throat 42 of a venturi generally indicated at numeral 43 in the drawings. The recirculating laundry liquid from the tub 18 enters the venturi through a relatively large diameter opening 44, the venturi assembly 43 being secured to the tub by means of an annular flange 46. In passing into the constricted throat portion 42, the laundry liquid passing into the conduit 27 creates a negative pressure exisiting at the orifice 41, which is sufiicient to draw the liquid additive from the container 33 into the conduit 36 and then through the orifice 41 into the recirculating laundry liquid. Thus, small amounts of bleach concentrate are continuously being injected into the circulating fluid stream as the recirculation progresses. Ultimately, most of the liquid 33 will be injected into the recirculating laundry liquid. In order to seal the discharge at the orifice 34, and prevent air from being entrained in the recirculating system, I may provide a floating ball 49 in the container 31, the ball 49 seating itself on the discharge orifice 34 when the liquid level drops sufficiently, and preventing air from being drawn into the system.

The check valve in the discharge orifice of the container 31, represented by the ball 49, is not always necessary, however, as the recirculation rate provided by the pump 24 can be controlled so that enough liquid is still retained in the conduit 36 to provide a liquid seal at all times and thereby prevent air from being entrained in the recirculation system.

From the foregoing, it will be apparent that the dispensing system of the present invention is quite simple and economical but still provides efi'icient dispensing of a liquidlaundry additive into the circulating laundry liquid. The control is automatic to the extent that no liquid is injected until laundry liquid is being circulated by the recirculating pump. Hence, it is impossible to inject the.

bleach or liquid additive prematurely where it might damage the fabrics or might interfere with the Washing action provided by the detergents. It should also be evident that this automatic dispensing system requires no expensive solenoids or control circuitry of any description but can be fabricated from inexpensive parts with a minimum of time in labor and assembly.

It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention,

The embodiments of the invention whichan ex elusive property or privilege is claimed are defined as follows:

1. In a laundry machine:

means forming a closed recirculation circuitcomprising a recirculation system,

recirculating means at one point in said circuit including a pump having an inletfrom and an outlet to said circuit for driving liquid in said circuit in the form of a stream at increased pressure, a a tub at a second point in said circuit for receiving and accumulating a pool of liquid in which articles to be washed may be placed for laundering, 1 a discharge conduit in said circuit interconnecting said outlet of said pump to said tub for carryin said stream of liquid to said tub, an inlet conduit in said circuit interconnecting said tub to the inlet of said pump for supplying liquid thereto, liquid level responsive means in control of said pump to operate said pump when liquid is at a preselected level in said tub, 1 means forming a venturi fitting in said circuit and having a venturi throat disposed in said inlet conduit between said first and second points in said circuit and through which all of the liquid in said closed circuit flows,

an additive storage container outside of said circuit and having a discharge throat,

a siphoning conduit means forming a siphoning loop and interconnecting said dischargethroat of said storage container and said means forming said venturi,

said siphoning loop being disposed above a maximum liquid level of 'said tub to prevent liquid in said tub from entering said storage container and to prevent the contents of said storage container from freely draining into said circuit, and means in said siphoning conduit forming an orifice in fluid communication with said venturi throat, whereby the contents of said storage container are siphoned from said container and admixed with said stream of liquid in said circuit on the upstream side of said pump only when sufliciently reduced pressure is provided at said venturi throat by a flow of liquid from said tub to said p p said storage container having a valve means therein closing said discharge throat when the supply of additive is depleted therefrom for preventing air from being entrained in the recirculating system.

References Cited 7/1961 Smith et a1 68-207 5/1963 Bochan 68--207 WILLIAM F. ODEA, Primary Examiner.

DAVID R. MATTHEWS, Assistant Examiner, 

1. IN A LAUNDRY MACHINE: MEANS FORMING A CLOSED RECIRCULATION CIRCUIT COMPRISING A RECIRCULATION SYSTEM, RECIRCULATING MEANS AT ONE POINT IN SAID CIRCUIT INCLUDING A PUMP HAVING AN INLET FROM AND AN OUTLET TO SAID CIRCUIT FOR DRIVING LIQUID IN SAID CIRCUIT IN THE FORM OF A STREAM AT INCREASED PRESSURE, A TUB AT A SECOND POINT IN SAID CIRCUIT FOR RECEIVING AND ACCUMULATING A POOL OF LIQUID IN WHICH ARTICLES TO BE WASHED MAY BE PLACED FOR LAUNDERING, A DISCHARGE CONDUIT IN SAID CIRCUIT INTERCONNECTING SAID OUTLET OF SAID PUMP TO SAID TUBE FOR CARRYING SAID STREAM OF LIQUID TO SAID TUB, AN INLET CONDUIT IN SAID CIRCUIT INTERCONNECTING SAID TUB TO THE INLET OF SAID PUMP FOR SUPPLYING LIQUID THERETO, LIQUID LEVEL RESPONSIVE MEANS IN CONTROL OF SAID PUMP TO OPERATE SAID PUMP WHEN LIQUID IS AT A PRESELECTED LEVEL IN SAID TUB, MEANS FOR FORMING A VENTURI FITTING IN SAID CIRCUIT AND HAVING A VENTURI THROAT DISPOSED IN SAID INLET CONDUIT BETWEEN SAID FIRST AND SECOND POINTS IN SAID CIRCUIT AND THROUGH WHICH ALL OF THE LIQUID IN SAID CLOSED CIRCUIT FLOWS, AN ADDITIVE STORAGE CONTAINER OUTSIDE OF SAID CIRCUIT AND HAVING A DISCHARGE THROAT, A SIPHONING CONDUIT MEANS FORMING A SIPHONING LOOP AND INTERCONNECTING SAID DISCHARGE THROAT OF SAID STORAGE CONTAINER AND SAID MEANS FORMING SAID VENTURI, SAID SIPHONING LOOP BEING DISPOSED ABOVE A MAXIMUM LIQUID LEVEL OF SAID TUB TO PREVENT LIQUID IN SAID TUB FROM ENTERING SAID STORAGE CONTAINER AND TO PREVENT THE CONTENTS OF SAID STORAGE CONTAINER FROM FREELY DRAINING INTO SAID CIRCUIT, AND MEANS IN SAID SIPHONING CONDUIT FORMING AN ORIFICE IN FLUID COMMUNICATION WITH SAID VENTURI THROAT, WHEREBY THE CONTENTS OF SAID STORAGE CONTAINER ARE SIPHONED FROM SAID CONTAINER AND ADMIXED WITH SAID STREAM OF LIQUID IN SAID CIRCUIT ON THE UPSTREAM SIDE OF SAID PUMP ONLY WHEN SUFFICIENTLY REDUCED PRESSURE IS PROVIDED AT SAID VENTURI THROAT BY A FLOW OF LIQUID FROM SAID TUB TO SAID PUMP, SAID STORAGE CONTAINER HAVING A VALVE MEANS THEREIN CLOSING SAID DISCHARGE THROAT WHEN THE SUPPLY OF ADDITIVE IS DEPLETED THEREFROM FOR PREVENTING AIR FORM BEING ENTRAINED IN THE RECIRCULATING SYSTEM. 